Signaling system for railroads



J. E. WILLING SIGNALING SYSTEM FOR RAILROADS Filed Feb. 17, .1932

5 TI HS 3 13 BY a fiATTQRNEY March 2, 193 7.

Patented Mar. 2, 1937 UNITED STATES PATENT OFFICE Joseph E. Willing, Rochester, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application February 17, 1932, Serial No. 593,549

12 Claims.

This invention relates to absolute-permissiveblock signaling systems for railroads, and more particularly to such a system employing direct current polarized home-distant relays of an improved type.

An absolute-permissive-block signaling system is a system in which a single track section is signaled for traffic moving in either direction, and a system which afiords the same protection and facility for trains following each other through the single track section as is afforded in modern signaling systems for tracks signaled for one direction of trafllc only, and in which an opposing train is prevented from entering a single track section already occupied by a train or trains. This facility of train signaling is accomplished by connecting the various home-distant relays for each direction of travel in tumble-down or repeater fashion, so that the de-energization of one relay causes the next relay in the rear to be de-energized, and so on through the entire track section, and in which a directional relay, such as a stick relay, is employed for closing an auxiliary circuit to the next home-distant relay in the rear of a signal at stop, completed in response to the movement of a train in the proper direction.

In signaling systems of the type mentioned, the home-distant relay should be slow to pick up,

in order to prevent the false or improper picking up of a directional stick relay, and such homedlstant relay should be slow to drop, so that the directional stick relay can be picked up under certain traflic conditions.

In accordance with the present invention it is proposed to use a polar neutral relay, as such home-distant relay, wherein a short circuited winding 60 of low resistance, or usual copper band is provided for making the relay slow to release 0 its neutral armature.

It is further proposed to include a resistance in series with the main winding of such homedistant relay, which resistance is short-circuited when the relay assumes its attracted position, in

order to render such relay slow to pick up, but

after being picked up, saturates the main magnetic circuit so as to induce a heavy current in the short circuited winding, to make it slow droppmg.

Another function performed by home-distant relays of this type is that upon pole changing of the main circuit for a relay, the neutral armature of such relay will be only momentarily deenergized whereby the slow action of subsequent 55 home-distant relays prevents what is known in signal parlance as a kick-off, which consists in momentary sequential de-energization of a series of home relays, this by reason of momentary de-energization of the first of these relays due to pole changing of its energizing circuit.

Other objects, purposes and characteristic features of the present invention will in part be obvious from the accompanying drawing and will in part be more fully described hereinafter.

In describing the invention in detail reference will be made to the accompanying drawing, which shows one embodiment of the invention applied to a portion of a single track section of a railway.

Referring to the drawing, the track rails l have been shown divided into blocks by insulating joints 2, of which the block I and the adjacent ends of two other blocks H and J only have been shown, and in which each block is further divided by insulating joints 3 to constitute a divided block having two track circuited sections each provided with a track circuit including a battery B (containing a suitable exponent) and a track relay T (containing a suitable exponent) At the entrance end to each block, for each direction of traflic, has been shown a light signal S (containing a proper exponent) of which the east-bound signals have been designated S and S and the west-bound signals have been designated S and S Since each of these signals is controlled in exactly the same way it will sufiice to describe the control circuits for the signal S like parts for controlling other signals being designated by reference characters having distinctive exponents. The signal S is controlled by home-distant relay HD and a track relay T a back contact of the directional stick relay being included in the energizing circuit for the home-distant relay HD for checking purposes. The home-distant relays for the signals S and S and the associated circuits have for convenience been omitted but are the same as those of. S and S respectively. It is believed that the invention is most readily understood by considering the operation of the system as effected by the movement of trains.

Operation Under normal clear traffic conditions, the home-distant relay HD is energized through the following circuit-beginning at the terminal (B+) of a suitable battery having its mid-point connected to the common return wire C, front contact H] of relay HD wires II and I3, back contact M of the stick relay 6S, wire l5, front contact N5 of the track relay T wire l1, back contact l8 of the opposing directional stick relay 58, wire is, front contact of the track relay T wire 2!, main winding of the relay HD, wire 22, resistance unit R Wires 23, 24, 25, C, and 25 to the mid-point of. said battery.

Let us first assume that a west-bound train, that is a train moving from right to left, is entering the block J. The entrance of this train will result in opening of the contact [6 (not shown) of the track relay T (not shown) thereby deenergizing the home-distant relay HD Dropping of the home-distant relay I-ID will result in opening of its contact in, thereby illuminating the danger aspect of signal S by lighting of the red lamp R. Further, opening of the contact ID of the relay HD will break the energizing circuit for the home-distant relay H13 heretofore traced, and this relay EU will in the same way de-energize the relay HD (not shown) in the rear thereof. This sequential de-energization of the home relays HD HD etc., is known as the tumble-down function, which blocks opposing trains, and prevents their entering a single track section already occupied by the train.

As the train in question passes the signals S and S these signals Will indicate traific conditions in advance, and will indicate traific conditions to other following trains, all in a manner as will be described hereinafter in connection with the operation of signals S and S Let us now assume that an east-bound train,

, moving from left to right enters the block H.

The entering of this train into the block H will result in tumbling down of the home relays for the signals S and S so that these signals S and S will assume their stop condition. As soon as this train in the block H passes into the second track circuit thereof containing the track relay T it will cause dropping of this track relay T and opening of its contact l6. At this time, assuming the existence of clear trafiic conditions in advance for east-bound trains, there is completed the following energizing circuit for the green lamp G:-beginning at the terminal (13+) of a suitable battery, front contact It" of the relay H13 wires H and I2 polar contact 31 assuming its right-hand position, wire 32, green lamp G of the signal S to the common return wire C connected to the mid-point of said battery.

Let us now assume that the train in question passes the signal S In so doing it effects deenergization of the track relay T Dropping of the contact 2!] of the track relay T breaks the energizing circuit for the relay HD but the rapid dying of flux in the main core structure of the relay HD causes a voltage to be induced in the secondary winding or slug 6!] of this relay, thereby causing current to flow therein and hold H33 up for a short time, and since the relays S are bruit to be quick acting, this period of time is sufficient for the directional stick relay As to be picked up through the following pick-up circuit:beginning at the terminal (3+) back contact 49 of the track relay T wires 4| and 42, front contact 43 of the relay HD wires 44 and 35, Winding of the stick relay is, to the common return wire C connected to the mid-point of, the local battery.

Closure of this circuit picks up the stick relay 48, which immediately upon closure of its stick contact ll will close the following stick circuit:- beginning at the terminal (B+) of the local battery, back contact 40 of the track relay T wires 4! and 46, stick contact 47 of the relay 45, wires 28 and 5, winding of the relay ts to the common return wire C. Immediately upon dropping of the relay I-ID an auxiliary stick circuit for the relay is is closed, which may readily be traced, and includes the back contact 43 of, the relay H13 and the stick contact 41 of the relay 48.

As soon as the east-bound train has passed entirely out of the block H, the contact 16 of the track relay T will be closed, thereby closing a caution circuit for the next home-distant relay in the rear, this caution circuit leading from the terminal (B), through front contact I4 of. the stick relay 5S, wire I5 front contact I6 of the track relay T wire ll back contact I8 of the stick relay 3S, line wire [9 etc.

Let us now assume that the east-bound train in question passes through the block I and enters the block J. This train will of course, assuming trafiflc conditions in advance to be favorable, find the signal lamp G of the signal S energized when it reaches this signal 8, all in a manner as already explained in connection with the signal S As this east-bound train enters the block J and de-energizes the track relay T it will pick up the directional stick relay BS, in a manner as already pointed out in connection with the directional stick relay 48.

As the rear end of the train passes entirely out of the block I, the home-distant relay HD, which was de-energized during the entire occupancy or" the block I is now energized to its lefthancl position through the following caution circuit-beginning at the terminal (B front contact M of the directional stick relay 68, wire 15, front contact l5 of the track relay T wire l7, back contact l8 of the stick relay 5S, wire i9, front contact 2L of the track relay T wire 2!, winding of the relay HD wire 22, resistance unit R wires 23, 24, 25, C, 25 and 26 to the mid-point of the battery. The closure of the circuit just traced will operate the relay HD to its left-hand dotted position, thereby placing the polar contact 3| in a position to energize the caution lamp Y, instead of the green lamp G, thereby informing an approaching train that there is a train in the second block in advance, namely in the block J.

Let us now assume that the train in question, which is now occupying the block J, passes entirely out of this block J. For reasons already explained the home-distant relay HD will now be energized by current of negative polarity, and thus will move its neutral contact 43 to its attracted position, thereby breaking the stick circuit for the directional stick relay (is, resulting in this relay 653 being de-energized and dropping its contact hi, as a result of which the normal circuit for the home-distant relay H1) is again complete, resulting in the application of current of positive polarity, instead of current of negative polarity, to the relay HD As the train in question now passes beyond the second block in advance of the signal S, this signal S will be returned to its normal clear position for reasons mentioned in connection with the signal 3*, so that the signal system will again assume its normal condition, as shown in the drawing.

Attention is now directed to the resistance unit R included in series with the relay HD". It will be noted that this resistance unit is normally short-circuited through a front contact 58 of the home-distant relay HD*. The purpose of this resistance R is to increase the time necessary for the relay HD to assume its neutral armature attracted position. The advantage in having this home-distant relay HD slow in picking "upmay be best explained by assuming a short train moving'at high speed from right to left in the block'I. As this train passes over the insulating joints 3, and if the track relay T is slow to drop, as a shunted track relay is, and the track relay T is quick to pick up as is usually the case, the home-distant relay HD will be momentarily energized during this rapid passage of a short train over the insulating joints 3, but the provision of the resistance R which is now included in series with the relay HD, the contact 50 being open, prevents the relay HD from momentarily picking up, it being understood that momentary picking up of the relay HD with the later de-energizing of the track relay T might pick up the stick relay is at a time when the directional stick relay is should not pick up to energize HD (not shown) to put signal S (not shown) to caution, to thus allow an east bound train, to run into the west bound trains. In applicants construction, however, the relay HD is sumciently slow to pick up to prevent such false picking up of the stick relay.

Applicant has thus proposed a system of single track signaling of the absolute-permissive-block type, which employs polar neutral relays which bytheir construction will not drop on momentary de-energization, and hence pole-changing, as of HD will not drop HD etc., and these relays have been provided with an auxiliary resistance R which causes these relays to be slow to pick up as is required in an absolute-permissive-block signaling system, thereby preventing accidental picking up of the opposing stick relay, and the slow dropping function obtained is taken advantage of to afford picking up of the associated stick relay, all in a manner as already pointed out in the foregoing description, so that a comparatively simple system of absolute-permissiveblock signaling employing a comparatively few relays, has been provided.

The above rather specific description of one form of the invention, has been given solely by way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, this invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications, are intended to be included by this invention, as come within the scope of the appended claims.

Having described my claim:-

1. In an absolute-permissive-block signaling system, the combination with a plurality of successive signals along a railway track, of a polar neutral relay for each signal each of which relays has slow release means connected to receive energy inductively from the main winding of such relay, a directional stick relay associated with each signal and picked up in response to a train passing the associated signal in the direction governed by said signal, a circuit for each polar neutral relay energized by current of one polarity and including a front contact of the next polar neutral relay in advance, and another circuit for each polar neutral relay energized by current of another polarity and including a front contact of the directional stick relay associated with the next polar neutral relay in advance.

2. In an absolute-permissive-block signaling invention, I now system, the combination with a plurality of successive signals along a railway track, of a polar neutral relay for each signal each of which relays has a short circuited winding positioned to receive energy inductively from the main winding of such relay, current restricting means included in series with the main winding of each of said relays, a front contact of each of said relays shunting said current restricting means, a. directional stick relay associated with each signal and picked up in response to a train passing the associated signal in the direction governed by said signal, a circuit for each polar neutral relay energized by current of one polarity and including a front contact of the next polar neutral relay in advance, and an other circuit for each polar neutral relay energized by current of another polarity and including a front contact of the directional stick relay associated with the next polar neutral relay in advance.

3. A railway signal system of the absolutepermissive block type, a light signal at each signal location, a home-distant relay controlling each signal, a directional stick relay for each homedistant relay, each home-distant relay being controlled by the home-distant relay and associated directional stick relay at the next signal location in advance, the home-distant relays for such system each comprising a polar neutral relay in which the neutral armature has associated therewith slow release means, polar and neutral contacts of said relays for controlling the aspects of the respective associated signals, and means associated with each of said home-distant relays to render it slow to pick up.

4. A railway signal system of the absolutepermissive block type, a light signal at each signal location, a home-distant relay controlling each signal, a directional stick relay for each homedistant relay, each home-distant relay being controlled by the home-distant relay and associated directional stick relay at the next signal location in advance, the home-distant relays for such system each comprising a polar neutral relay in which the neutral armature has slow release means, polar and neutral contacts of said relays for controlling the aspects of the respective associated signals, and current restricting means included in series with the main winding of said polar neutral relay only when such relay is in its de-energized condition.

5. In combination, in an A. P. B. system employing light signals, at each location, a home-distant relay having an energizing circuit controlled in accordance with trafiic, a directional stick relay energized in accordance with traffic and through a contact of the home-distant relay, and current limiting means in the energizing circuit for the home-distant relay to make it slow to pick up.

6. In combination, in an A. P. B. system employing light signals, at each location, a homedistant relay having an energizing circuit controlled in accordance with trailic, a directional stick relay energized in accordance with traffic and through a contact of the home-distant relay, and a resistance in the energizing circuit for the home-distant relay to make it slow to pick up.

'7. In combination, in an A. P. B. system employing light signals, at each location, a homedistant relay having an energizing circuit controlled in accordance with traffic, a directional stick relay energized in accordance with traflic and through a contact of the home-distant relay, and a resistance, shunted at times by a contact on the home-distant relay, in the energizing circuit for the home-distant relay to make it slow to pick up.

8. In combination, in an A. P. B. system employing light signals, at each location, a homedistant relay having an energizing circuit controlled in accordance with traific, a directional stick relay energized in accordance with traific and through a contact of the home-distant relay, and a resistance, shunted at times by a back contact on the home-distant relay, in the energizing circuit for the home-distant relay to make it slow to pick up.

9. In combination, in an A. P. B. system employing light signals, at each location, a homedistant relay having an energizing circuit controlled in accordance with traffic, a directional stick relay energized in accordance with traffic and through a contact of the home-distant relay, and a resistance in the energizing circuit for the home-distant relay to make it slow to pick up, and means making the home-distant relay slow to release.

10. In combination, in an A. P. B. system employing light signals, at each location, a homedistant relay having an energizing circuit controlled in accordance with trafiic, a directional stick relay energized in accordance with trailic and through a contact of the home-distant relay, and a resistance, shunted at times by a contact on the home-distant relay, in the energizing circuit for the home-distant relay to make it slow to pick up, and means making the home-distant relay slow to release.

11. In combination, in an A. P. B. system, a home-distant relay having an energizing circuit controlled in accordance with trafiic, a directional stick relay energized in accordance with trafiic and through a front contact of the home-distant relay, and a resistance, shunted at times by a contact on the home-distant relay, in the energizing circuit for the home-distant relay to make it slow to pick up, whereby to prevent momentary closure of the circuit of the home-distant relay due to control by trafiic from effecting pick-up of said-stick relay, and means making the homedistant relay slow to release.

12. In combination, in an A. P. B. system, a home-distant relay having an energizing circuit controlled in accordance with traiiic, a directional stick relay energized in accordance with trallic and through a contact of the home-distant relay, and a resistance in the energizing circuit for the home-distant relay to make it slow to pick up, whereby to prevent momentary closure of the energizing circuit of the home-distant relay due to control by trafiic from effecting pick-up of said stick relay.

JOSEPH E. WILLING. 

